This November, DC’s superhero universe of Superman, Lex Luthor and the Justice League will come face to face with the characters from the classic comic book series Watchmen in the upcoming mini-series Doomsday Clock — and series writer (and president of DC Films) Geoff Johns stars in a new video explaining how the story came to be.

“It’s unlike any story I’ve ever written, and any story [artist Gary Frank has] ever drawn,” Johns says of the 12-issue project in the video, before going on to remind the audience that his last comic book project — 2016’s DC Universe: Rebirth special issue — set the scene for the first crossover between the DC Universe and the Watchmen universe.

“Both of us were, rightly so, nervous about it,” Johns admits of introducing the two fictional worlds. “We want to do our own thing, but play into some of the structural tenets that [Watchmen] created, some of the dynamics and some of the tones it created.” Watch the teaser video below for more of Johns’ insights into the origin of the series.

Doomsday Clock No. 1 will be released digitally and in comic book stores Nov. 22. Johns will be talking about it in more depth at the upcoming New York Comic Con, which runs Oct. 5 through Oct. 9 at the Javits Center in New York City.